


The Island of Dr. Clark

by hectocotyle



Series: liquidmantis shenanigans [9]
Category: Metal Gear
Genre: Anal Sex, Animal Transformation, Asexual Character, Blow Jobs, Body Horror, Dubious Science, Mild Gore, Mildly Dubious Consent, Non-Human Genitalia, Nonbinary Character, Other, Oviposition, Sex with Sentient Animals, an 'NVE' if you will, liquid has a near-vore experience, monster kink, though not with an actual egg
Language: English
Status: Completed
Published: 2017-12-13
Updated: 2017-12-13
Packaged: 2019-02-14 09:46:33
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,322
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13005105
Author URL: https://archiveofourown.org/users/hectocotyle/pseuds/hectocotyle
Summary: Desperate to ditch his human body, Mantis "volunteers" as a test subject for an experiment in transgenics.[For the2017 Supply Dropwisher who wanted liquidmantis bugfuck. Just @ me next time tbh]





	The Island of Dr. Clark

<You don't really _believe_ that baloney, do you? >

Liquid glances up at Mantis as the pair of them head for Dr. Clark's lab. <What baloney?>

Mantis's thought-speak is dismissive. <The doc reckons that by the end of the year we'll have Genome Soldiers who can turn into polar bears at will. Just flip animal mode on, like a psychic light switch, and fight the bad guys with your new superpowers. You have to admit it sounds more like a sci-fi book series for ten-year-olds than a project warranting legitimate government funding.>

<It could be possible. What do I know about transgenics? She's given us results in the past, and that's all I care about.>

Mantis gives a dubious sniff.

<You're the one who offered to help Dr. Clark study the psychological effects on the test subjects,> Liquid points out.

<I never said I thought the experiment was a _complete_ waste of time, > says Mantis. <I can see us improving the Genome Soldiers' ability to see and hear in the middle of a blizzard, enhancing their tolerance for extreme cold, that sort of thing. Anyway, you sign my paycheck, so I guess I'd better at least pretend to be working.>

Liquid bats at him with a laugh, but instead of connecting with its target, his hand swipes through empty space.

Mantis blips back into existence just above Liquid's head. <Shame we can't give the soldiers teleportation genes, huh?>

Liquid cranes his neck back to make a face at him. <Show-off.>

\----------

Over the course of the following weeks, Mantis spends more and more time helping Dr. Clark. She sends Liquid regular updates on the success of the preliminary human trials, to which he nods along politely; when it comes to the life sciences, he doesn't know his ass from a hole in the ground. That's what he pays _her_ for.

<I don't know about you, but I still don't see any of our guys sprouting white fur and complaining of a sudden craving for seal blubber,> says Mantis one day. <Though don't get me wrong, they do complain. About their incision sites getting itchy and sore under the bandages, mostly. Babies.>

Another couple of months into the project, he starts pulling overnight shifts, implausible as it seems for someone who perpetually looks about a hair's breadth from plunging into a coma. On those nights Liquid keeps half-dragging himself out of sleep fumbling in the dark for his pointy-edged cuddlebug.

He hopes Dr. Clark won't need Mantis for too much longer.

\----------

It happens as Liquid's preparing for yet another night without Mantis in his bed.

He's just tossed his coat onto his desk chair when his face... it's like his face simply explodes open.

The pain defies description. He can't even draw breath to scream. Yet when he claps his hands to his cheeks, he can tell there's nothing changed about him. No blood. Everything where it should be.

Which means this isn't Liquid's pain.

<Mantis? Are you all right?>

Silence.

<Answer me, Mantis!> Liquid snaps, worry sending a hot pulse of anger through him.

And he receives an answer, in the form of a phantom pair of extra limbs punching out of his ribcage like a chestburster from one of those _Alien_ films. The renewed agony makes his knees buckle, and he can only lie helpless on his side, writhing and gasping as he shares Mantis's pain.

Other phantom feelings make themselves known. His skin tightens and hardens as if he's been dipped in a vat of enamel paint. There's a series of awful grinding, crunching sensations as his limbs—all six of them—stretch out to hideous lengths and develop joints in unnatural places.

His bones dissolve into jelly, then water, then nothing. His internal organs slosh past one another, changing shape, rearranging themselves in bizarre ways. His lower abdomen bloats obscenely, creating a massive body cavity that extends well beyond his legs, and some of the mutated organs migrate down into it with a sickening squelchy sensation.

The whole process lasts less than a minute, but it leaves Liquid panting and sweat-drenched.

He staggers to his feet, powering through the terrible weakness in his abused muscles, and blunders over to the door.

Dr. Clark's laboratory wing is a ten-minute walk from his quarters, but with fear for Mantis fueling him, he makes it there in half that time, impatiently shoving aside anyone who slows him down with their inane questions.

He weaves through the laboratory corridors, homing in on Mantis with their mind link as his guide.

There! An ordinary-looking beige door in a hall full of identical beige doors. On the wall beside it is a small dry-erase board with "MANTODEA - SUBJECT 001 - FINAL STAGE INFUSION" neatly written on it in marker.

Dr. Clark is going to have an awful lot of explaining to do. An _awful fucking lot_.

Whoever last went through the door left it open a crack. Inside is what looks more or less like a standard hospital room, with two beds separated by a divider curtain.

The floor surrounding the bed closer to the door is a chaotic jumble of catheters, their ends lying in steadily growing puddles of half a dozen different IV fluids. The vital sign monitor mounted to the wall behind the bed emits a shrill alarm beep every few seconds. Electronic numbers and symbols glow a ghostly green in the semidarkness.

But it's not the monitor that commands Liquid's attention.

It appears from the shadows behind the half-drawn divider curtain with unhurried, almost mincing steps of its dainty forefeet. Dainty forefeet that look terribly out of place extending from the wickedly hooked tips of a pair of predatory grasping claws.

"My God," Liquid whispers.

Mantis—because who else could it be?—snaps his head in Liquid's direction at the sound of his voice.

Liquid walks over to him, hands raised in a calming gesture. He figures Mantis could use some calming after his grisly ordeal.

<We're going to fix this,> he tells him, switching back to thought-speak. <I don't know what Clark is playing at, but we're going to—>

He cuts himself off as tendrils of ice ensnare his guts.

The white sheets of the bed behind Mantis are spattered with dark stains. Shreds of clothing litter the floor beside it.

Shreds of a medical orderly's uniform.

Mantis takes a step toward Liquid.

Liquid takes a step back.

<Mantis,> he says in the firmest tone he can manage with his flesh crawling as if he's got a whole colony of ants swarming over him.

He doesn't even see Mantis strike. One millisecond he's standing, the next he's a meter off the ground, shoulders pinched painfully in the gigantic bug's raptorial forelimbs, staring into those dead insect eyes.

The inside of Mantis's mouth is an unpleasant Pepto-Bismol pink.

Liquid screams. He can't help it. He screams and twists and thrashes, but he's no match for the wiry strength in those arthropod legs.

"Mantis, stop!" he cries, slamming his eyelids shut as those bladed mandibles begin pressing into his cheeks. Slicing him open. Oh, Christ, eating him! "MANTIS!"

Through the fog of terror, he almost doesn't notice the monstrous insect's hesitation.

A blind drop, and his back thumps against the hard floor, knocking the wind out of him. His eyes snap open to see Mantis looming over him like a figure from a nightmare.

Liquid skitters out from under the insect, backing away until he hits the wall. The bug makes no move to attack him again, just stares at him with those empty eyes, antennae swaying as if stirred by a gentle breeze.

Liquid returns the look warily, and hates himself for it. If Mantis really is still in there—to some degree or another—maybe he's realized that for the first time in his life Liquid is afraid of him. Like the poor thing hasn't suffered enough for one day.

The little feelers around his mouthparts twitch while he watches Liquid start to wipe away the blood trickling from the twin cuts his mandibles inflicted.

<I'm all right,> he tells him. <Won't even need stitches.>

Mantis slinks over to him and bends down. Liquid stiffens. But all the giant bug does is use the very tips of his mouthparts to ever-so-carefully scoop up the remaining blood.

It doesn't hurt at all. Kind of tickles, actually.

Liquid pats his strange, expressionless mask of a face. <Thanks.>

He climbs to his feet right as a couple of orderlies sweep into the room. "Oh, good, someone finally decided to show up. I'd like to speak with Dr. Clark. In person."

The orderlies take turns gaping at Mantis, at Liquid, at each other.

"I'd get busy. You don't want to know what became of the last attendant who came in to check up on Mantis. And I happen to know he's still hungry."

"Dr. Clark prefers not to be seen in person," quavers one orderly at last.

"Fine," Liquid says with a shrug. "Mantis, eat them."

He only meant to scare some sense into them. Really. But truth be told, he's so furious with Dr. Clark, and by extension everyone working for her, that it's hard to feel sorry for the hapless orderly who finds himself snatched up and shrieking in Mantis's claws.

"Bring me Dr. Clark," Liquid says pleasantly to the other attendant.

\----------

"Hypnotic suggestion," she says. "How else could he have done it? He forced my staff to treat him with doctored DNA, over the course of months by the looks of it, and none of us were any the wiser."

He should have known.

From the big show Mantis made of doubting the experiment, he should have guessed something was up.

"Why didn't he say anything to me?" he asks quietly, his anger deflating.

"Would you have let him go through with the treatment? In his physical condition?" replies Dr. Clark. "No! Of course not! Neither would I! We have plenty of volunteers who _don't_ look ready to keel over from the next light wind. It'd be a waste of a psychic."

"And if he wants to change back?" Liquid demands.

Dr. Clark nods as if in response to his unspoken worry. "You said it yourself: His mind is still in there, even if it's sharing space with animal instinct now. The transformation was designed from the get-go to be reversible. If he doesn't change back, it's likely because he chooses not to." She steals a glance at Mantis, who's perched off in a corner nibble-cleaning his forefeet like none of this has anything to do with him, and her expression hardens. "Now, if your friend Kamacuras here is through eating my employees and wasting our time and resources, I have work to get back to."

\----------

After the initial shock wears off, Dr. Clark's staff lose interest in Mantis as quickly as she did. The transformation process was designed to be triggered by thought command, but Mantis had—has—a rather more powerful brain than the average person. They can hardly expect to replicate his results with the other test subjects.

Which is all well and good as far as Liquid is concerned. He won't have Mantis treated like a lab rat.

There is, however, the minor issue of keeping him fed.

Before his transformation, he barely ate enough from day to day to keep his organs from shutting down. Really, it's a nice change of pace, seeing him display such a healthy appetite. As long as you don't count the whole "considers human beings a potential menu item" thing.

Well, he thinks dryly, Mantis did just have a nice big meal. It can wait until morning.

He decides to let Mantis continue to share a room with him. Yes, this is probably an ill-advised course of action. No, he doesn't care. What's he supposed to do, lock his best friend up in a cage?

"Over my dead body," he mumbles as he hauls stacks of documents into the closet to free up some floor space. It's a tight fit in here for a bug the size of a giraffe.

He hears the leathery rustle of wings and looks behind him to find Mantis's huge, unblinking eyes fixed on him. He suppresses a shudder.

<If you get the munchies in the middle of the night, wake me up so I can bring you something instead of snacking on me, okay?> he says, a weak stab at a joke. <And while we're on the subject, please don't eat any more people. Unless it's someone I really don't care for. In which case, well, accidents will happen.>

More wordless staring. Impossible to know what's going on in that amalgamate brain. Their mind link is still there, he can sense that clearly enough, but just how much Mantis understands is anyone's guess.

Doubt twists his stomach in a slow knot. How is he meant to deal with all this?

Sniper Wolf. That's who he needs right now. Not many anxieties getting smashed into the bed frame with a really big strap-on can't help. He just hopes she's in the mood.

Mantis sweeps his long, slender antennae downward to brush them all over Liquid's chest and stomach. Laughing, he lightly slaps them away. <What's got into you now?>

Without warning, the bug reaches out with one forefoot and knocks him on his butt.

<What the—> Mantis plants the foot on his chest, shoves him flat on his back. His heart thunders, and he can feel the throbbing in the freshly scabbed-over cuts on his cheeks. <Hey!>

Then Mantis's open jaws descend on his crotch, and he damn near passes out.

RRRRIP!

Well, there go a perfectly good pair of pants, he thinks with absurd calmness, like his brain is trying to protect itself from this new insanity.

With the tip of his beaklike mouth, Mantis nudges Liquid's dick out of the ragged hole. His own mouth hanging open stupidly, he watches his most prized possession disappear into that hell-tunnel of organic razor blades.

Transfixed by bafflement as much as horror, it takes him several seconds to comprehend that Mantis is not, in fact, devouring his dick. At least not in the literal sense. Actually, the light, insect-spit-lubricated pulling on the loose skin of his cock doesn't feel too bad. Those mouthparts must be capable of pretty delicate work, he supposes, if Mantis can use them to groom his fragile-looking forefeet.

Hey, genius, pipes up a more primal part of his brain. _Psycho Mantis is sucking your dick._ Consider enjoying it while it lasts, maybe?

"Mmm," he murmurs in agreement, relaxing his tense muscles and placing an encouraging hand on the side of the bug's smooth-shelled face. His dick gives a healthy jump, plumping up with blood in Mantis's busy mouth. The same mouth that ground up a couple of people into oatmeal while they were still alive and screaming. The same mouth that came way too close to doing that to _him_. Which should not be a turn-on. Not to any sane man.

Life's full of little surprises, isn't it?

<What about you?> he asks. Mantis pauses as if to pay attention. <I mean, how does a bug... y'know.> He waves a hand vaguely.

The insect just crouches there frozen, Liquid's cock still twitching in his mouth.

<Never mind,> he mutters. Obviously Mantis doesn't grasp the meaning of—

But he drops Liquid's dick, backs up a couple of paces, and curls his flexible abdomen around. From within the tip uncoils the strangest set of genitalia imaginable: an asymmetric pair of tendrils, the same glistening, nausea-inducing shade of pink as the inside of Mantis's jaws. The left tendril, the longer, thinner one, ends in—is that a _hook_? Jesus, that's a _hook_. Why are bugs _like_ this?

The right tendril, on the other hand, is nice and fat (and, more to the point, hookless). Liquid launches onto all fours and scuttles over for a closer look. <Not to be crass,> he says, taking the organ in hand, <but I need this thing in my ass STAT.>

The tendril winds around his hand, then releases it, leaving behind a slippery, clear residue.

Sounds like a yes to him. Yanking his ruined pants down so they bunch about his knees, he turns around, bends over, and reaches a hand back to eagerly guide Mantis's gross insect dick-tentacle into his ass.

It glides right in, gloriously smooth and slick, until he's taken as much as will fit. The exotic shape of it fills him so well, it's like he was born to take horrible bug-monster cock. (Fine by him.) Overwhelmed, he nearly collapses before he can plant both hands on the floor, fingers splayed, to brace himself.

Mantis observes all this without comment. Not that he expects commentary. It makes him a little sad. Things aren't the same without Mantis always offering his sarcastic two cents.

Well, nothing for it but to get the sadness fucked out of him.

He's hardly completed the thought when Mantis starts plowing him. The bug's thrusting is jerky, clumsy, plainly inexperienced, but that doesn't stop Liquid's toes curling inside his boots, or his tongue lolling out, dripping frothy drool onto the floor.

As he fucks him, Mantis places a hind foot on the back of his neck and presses down. Not hard enough to move him. More like he's asking permission.

With a noisy moan, Liquid lets the bug pin him to the ground. It's a humiliating position, ass in the air, cheek lying in a puddle of his own drool, and it's quite possibly the hottest thing he's ever experienced.

While all this is happening, the hooked tendril sort of wriggles and prods at his side. Looking for something to do, maybe. In a flash of inspiration, he grabs it and guides it to his dick. Mantis requires no further prompting. He twines the tendril around Liquid's hard-on and starts jerking him off even as he hammers his ass with the other tendril.

Ha! How many humans can pull that off with just their dicks?

Deluging his friend with telepathic praise, he bites down on his lip until he tastes blood. It'd be just his luck if a sentry heard him screaming himself hoarse and busted the door down.

Speaking of busting, he nuts all over the floor, cock pulsing forcefully in Mantis's coils. A sharp, giddy shout rakes his throat. So much for keeping the volume down.

Mantis keeps going and Liquid is happy to lie there and take it, squirming and grunting with the pleasure-pain of overstimulation. After a bit, the bug slows to a stop. His abdomen ripples slightly, ripples again, and Liquid feels the big tendril deposit some round, solid object into his ass. Then Mantis pulls out, leaving the object inside of him, and releases his neck.

Rising unsteadily to his knees, Liquid pushes the object out, wincing at the sudden sensation of emptiness. He picks it up: an off-white sphere the size of a small grapefruit, made of something like firm jelly. <An egg?> he says, incredulous. <Did you lay an egg in me?> He holds the thing out to Mantis to show him.

The bug considers it for a moment, then snatches it out of his hand and eats it.

<Oookay, I guess that answers the question of what to do with it.>

Giant praying mantis monsters aren't exactly built for cuddling, but Liquid's not about to let that stop him. He sits with legs crossed and pulls that terrifying-yet-oddly-beautiful head into his lap, embracing him, stroking his face and antennae.

Mantis doesn't make any sounds of pleasure—maybe that's not something bugs do—but he doesn't pull away, either.

<We'll be okay,> Liquid murmurs, petting him under the chin. His mouth-feelers shiver with each stroke. <We'll figure this out.>

He goes to sleep that night with Mantis perched by his bedside like a gargoyle protecting a cathedral.

 

**Author's Note:**

> i miiight expand on this if the mood strikes me
> 
> the animorphs influence is pretty obvious here but the transgenics angle was inspired by [dr. franklin's island](https://www.amazon.com/Dr-Franklins-Island-Readers-Circle/dp/0440237815), another favorite "body-horror animal transformation" story from my childhood
> 
> (mantis's "egg" is actually a [spermatophore](https://en.wikipedia.org/wiki/Spermatophore), btw)


End file.
